Power measurement device, determination method, and recording medium for identification of current detection element disposed in an incorrect direction

Patent metadata

Field	Value
Publication number	US-9869704-B2
Application number	US-201414890655-A
Country	US
Kind code	B2
Filing date	Jun 2, 2014
Priority date	Jun 13, 2013
Publication date	Jan 16, 2018
Grant date	Jan 16, 2018

Abstract

A power measurer measures, for each current transformer CT, electric energy supplied to equipment or electric energy supplied from the equipment based on a current measured by a current measurer and a voltage measured by a voltage measurer. A sign memory stores, for each current transformer CT, information indicating whether the electric energy measured by the power measurer when the current transformer CT is disposed in a correct direction on a power line shows a positive sign or a negative sign. A determiner determines that, when the sign stored in the sign memory differs from the sign of the electric energy measured by the power measurer, the current transformer CT is disposed in an incorrect direction on the power line.

First claim

The invention claimed is:

1. A power measurement device comprising:
a voltage measurer connected with a plurality of power lines feeding power in a plurality of phases, the voltage measurer being configured to measure a voltage in each phase of the plurality of phases;
a current measurer configured to measure, through a plurality of current detection elements each disposed on a power line of the plurality of power lines, a current input to equipment connected with the power line, or a current output by the equipment, for each of the plurality of current detection elements;
a power measurer configured to measure, for each current detection element, electric energy supplied to the equipment or electric energy supplied from the equipment based on the current measured by the current measurer and the voltage measured by the voltage measurer;
a sign table memory configured to store a sign table indicating which of a positive sign, a negative sign, and both positive and negative signs the electric energy measured by the power measurer should have when the current detection element is disposed in a correct direction on the power line for each power line;
an acceptor configured to accept, from a user, disposition information indicating on which power line the current detection element is disposed, for each of the current detection elements;
a sign information generator configured to generate sign information indicating which of a positive sign, a negative sign, and both positive and negative signs the electric energy measured by the power measurer should have when the current detection element is disposed in a correct direction on the power line based on the sign table stored in the sign table memory and the disposition information accepted by the acceptor, for each of the plurality of current detection elements;
a sign information memory configured to store the sign information generated by the sign information generator; and
a controller configured to determine that, when a sign indicated by the sign information stored in the sign information memory is inconsistent with a sign of the electric energy measured by the power measurer, the current detection element is disposed in an incorrect direction on the power line.

2. The power measurement device according to claim 1 , wherein:
the power line connected with the equipment is connected to one terminal of a master switch;
distribution lines are connected to another terminal of the master switch;
a further current detection element is disposed on a distribution line of the distribution lines;
the power measurer is further configured to measure electric energy supplied to, through the distribution line connected with the master switch, an external load;
the sign information indicates which of the positive sign, the negative sign, and both positive and negative signs the electric energy measured by the power measurer should have when the current detection element is disposed in the correct direction on the power line;
the power measurement device further comprises:
a current determiner configured to determine, based on a sign of the electric energy measured by the power measurer, whether or not a current flows from the distribution line to the external load;
a specifier configured to specify, based on the sign of the electric energy measured by the power measurer, the power line causing the current output by the equipment to flow when the current determiner determines that the current flows from the distribution line to the external load;
a total value determiner configured to determine whether or not electric energy supplied to the external load through the distribution line and acquired based on the electric energy measured by the power measurer is equal to or smaller than a total value of electric energy supplied through the power line specified by the specifier and acquired based on the electric energy measured by the power measurer; and
an incorrect disposition determiner configured to determine that, when the total value determiner determines that the electric energy supplied to the external load exceeds the total value, the current detection element is disposed in an incorrect direction on the power line.

3. The power measurement device according to claim 1 , further comprising a notifier configured to give a notification that the current detection element is disposed in an incorrect direction on the power line when the current detection element is determined to be disposed in an incorrect direction on the power line.

4. The power measurement device according to claim 1 , wherein:
the voltage measurer is configured to measure the voltage in each phase through a terminal connected with the power line;
the power measurement device further comprises:
a voltage determiner configured to determine whether or not the voltage in each phase measured by the voltage measurer is within a predetermined range; and
a notifier configured to give a notification that the terminal is falsely connected with the power line when the measured voltage in each phase is determined to be out of the predetermined range.

5. The power measurement device according to claim 1 , further comprising an outputter configured to output, when the current detection element is determined to be disposed in a correct direction on the power line, the electric energy measured by the power measurer to an external device.

6. A determination method to determine whether or not a current detection element of a plurality of current detection elements is disposed in a correct direction, the method comprising:
measuring a voltage in each phase of a plurality of phases applied to a plurality of power lines feeding power in the plurality of phases;
measuring, through the plurality of current detection elements disposed on the plurality of power lines, a current input to equipment connected with the power line, or a current output by the equipment for each of the plurality of current detection elements;
measuring, for each current detection element, electric energy supplied to the equipment or electric energy supplied from the equipment based on the measured current and the measured voltage;
storing a sign table indicating which of a positive sign, a negative sign and both positive and negative signs the measured electric energy should have when the current detection element is disposed in a correct direction on the power line for each power line;
accepting, from a user, disposition information indicating on which power line the current detection element is disposed, for each of the plurality of current detection elements;
generating sign information indicating which of a positive sign, negative sign and both positive and negative signs the measured electric energy should have when the current detection element is disposed in a correct direction on the power line based on the stored sign table and the accepted disposition information for each of the plurality of current detection elements;
storing the generated sign information; and
determining that, when a sign indicated by the stored sign information is inconsistent with a sign of the measured electric energy, the current detection element is disposed in an incorrect direction on the power line.

7. A non-transitory computer readable recording medium having stored therein a program for causing a computer to function as:
a voltage measuring function of receiving, from a voltage measurer being configured to measure a voltage in each phase of a plurality of phases applied to a plurality of power lines feeding power in the plurality of phases, a measured value of the voltage in each phase;
a current measuring function of receiving a measured value of the current, from a current measurer configured to measure

Assignees

• Mitsubishi Electric Corp

Inventors

• Ishihara Masahiro
• Koizumi Yoshiaki

Classifications

• G01R31/67

  Testing the correctness of wire connections in electric apparatus or circuits · CPC title

• G01R35/04

  of instruments for measuring time integral of power or current · CPC title

• G01R19/2513

  Arrangements for monitoring electric power systems, e.g. power lines or loads; Logging · CPC title

• G01R19/14

  Indicating direction of current; Indicating polarity of voltage · CPC title

• G01R22/10

  using digital techniques · CPC title